Minerals and Electrolytes: Why a varied diet isn’t enough (anymore)

Minerals and electrolytes are essential to life itself. Elements such as calcium, magnesium, potassium, sodium and chloride are integral to bodily functions: from muscle contractions to brain power, from bone strength to hydration maintenance.

"Just eat a varied diet and you'll get enough". This is a statement we are regularly confronted with, but is it accurate?

Historically, perhaps. A varied diet rich in fruits, vegetables, grains, and proteins may have been sufficient to meet daily needs until mid 20th century. However, modern agricultural practices, soil depletion, and breeding for yield over nutrition have led to a significant decline in the nutrient density of common foods. 

This article explores recommended daily intakes (RDIs) and evidence of nutrient decline, pointing to the conclusion that even a balanced diet may fall short today.

Recommended Daily Intakes for key minerals and electrolytes

Health authorities in each country establish RDIs to guide adequate consumption. The table below summarises these for essential minerals and electrolytes (values averaged for males and females where they differ slightly), based on UK dietary guidelines.

Nutrient density decline in common foods

Several studies (such as the ominously titled "The Biggest Challenge for Future Generations’ Health") reveal alarming drops in nutrient levels over decades, attributed to intensive farming, soil erosion, and high-yield crop varieties that dilute minerals. For instance, a review of USDA data from 1950 to 1999 showed declines in 43 fruits and vegetables. Another analysis from 1975 to 1997 found calcium down 27% and iron 37% in 12 vegetables. British data from 1930 to 1980 indicated calcium reduced by 19%, iron by 22%, and potassium by 14% in 20 vegetables.

To illustrate the impact, consider how many servings of specific foods were required in the 1940s (based on higher historical nutrient densities) versus today to meet RDIs. Calculations use average decline percentages and standard serving sizes (e.g., 100g for vegetables, one slice for bread).

The double-whammy impact of modern lifestyles

Clearly, increasing food portions by 30-60% just to meed RDIs is impractical. To make matters worse, we would question the validity of these RDIs today. Modern lifestyles, with increased psychological and environmental stress from work, screens, and urban living, may necessitate higher RDIs for minerals and electrolytes.

There is documented evidence to show that stress boosts metabolic demands, inflammation, and excretion of nutrients like magnesium, zinc, calcium, and iron, leading to depletion. For instance, chronic stress increases urinary magnesium loss, potentially linking to anxiety and fatigue. Higher intakes could mitigate this.

So we have a situation where nutrient density of foods has gone down in key minerals compared to just 80 years ago, while over the same period our requirements for these very same minerals have actually increased. 

In conclusion, relying solely on a varied diet overlooks nutrient dilution and modern demands. Supplementation or nutrient-dense sourcing appears to be necessary to prevent subclinical deficiencies.